This project aims to generate and utilize a biotinylated affinity probe of a recently isolated natural product. Although initial efforts were focused on a total synthesis, we have subsequently obtained sufficient quantities of the natural product to functionalize it directly with a biotinylated tag. Direct functionalization of the natural product has already been accomplished at a position predicted to not interfere with putative target binding due to known SAR. This work will enable access to analogs and model compounds that will enable the understanding of structure-activity relationships, as well as the mode of binding to the ligase. For example, we believe that this molecule may be a cysteine-reactive compound. An affinity probe containing a biotinylated or fluorescent affinity/imaging tag that will be critical for understanding the molecular mechanism of action. A synthesis of this probe has already been completed, and pulldown studies are currently underway to identify the ligase of interest unambiguously as a binding protein and target of the natural product.